US2296306A - Nondiffusing metallic salt coupler compound - Google Patents

Description

l 1942- w.b. PETERSON 2,

- NONDIFFUSING METALLIC SALT COUPLER COMPOUNDS;

' Filed Sept. 29, 1939 Fig 1 l N SILVER HALIDE LAYER CONTAINING'THE SILVER 5m m OFA HETEROCYCUC-RING-CONTA|NIHG COUPLER SUPPORT Fig.2;

BLUE SENSITIVE}LAYERS conmume SILVER BEEN SENSITIVE SALT OFA HETEROCYCLIC- mmmwmvm;

- RED SENSITIVE RING- CONTAINING COUPLER SUPPORT Patented Sept. 22, 1942 COBIPO UND Willard 1). Peterson, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application September 29, 1939, Serial No. 297,153 In Great Britain October 26, 1938 5 Claims.

This invention relates to photographic color forming or coupling compounds and particularly to coupler compounds which are non-diffusing when incorporated in sensitive emulsion layers.

The product of photographic images by means 01. a coupling reaction between a photographic developer and an intermediate or coupling compound upon which photographic development is well known, having been described in Fischer;

U. S. Patent 1,055,155 and numerous patents 0 which have issued more recently. One method of carrying out a color forming of this type is to incorporate the coupling compound in the sensitive emulsion layer prior to coating it on the support. When the coupling compound is incorporated in the sensitive layer in this way, a number of requirements must be met. Probably the most important of these is that the coupling compound must not wander or. diffuse from the layer in which it is incorporated. This is especially important when two or more layers are superposed and are differentially sensitive, as obviously the. wandering of a coupling component would cause inaccurate color rendition. Another requirement is that the coupling compound, when incorporated in the sensitive layer, should not desensitize or otherwise adversely affect the emulsion layer. 7 I I I have found that these requirements for coupling components may be attained by the use of derivatives of well known coupling compounds with certain heterocyclic compounds containing active groups in which a metal atom may be substituted to render the compound as a whole nondifiusing.

the coupling compounds are characterized by the fact that they contain an imino (NH) group in .the nucleus. These heterocyclic nuclei may also contain an SH group in the nucleus and the hydrogen atom of either the NH or the SH group may be replaced by a metallic atom such as a silver atom.

In the accompanying drawing, Fig. 1 is an enlarged sectional view of a single-layer element, and Fig. 2 is an enlarge'd sectional view of a three-layer element containing in the emulsion layers the silver salt of a heterocyclic-ring containing coupler.

The heterocyciic nuclei suitable for incorporating into coupler compounds according to my invention are characterized by the fact that the imino group which they contain is not more than two atoms distant from an atom which has an unshared pair 01' electrons. The atom which has the unshared pair of electrons may be, for

example, a nitrogen atom or a sulfur atom and may be in the heterocyclic ring or attached to an atom which is a member of the ring. It is a well known principle of chemistry that nitrogen v 85 The heterocyclic compounds which react with may exist with valences of either three or five and that sulfur may exist with valences of two, four or six. When nitrogen has a valence of three, it has therefore an unshared pair of electrons and when sulfur has a valence of two, it has one or two unshared pairs of electrons.

The following are suitable heterocyclic compounds into which coupling groups may be introduced to form compounds capable of being rentiered non-diffusing according to my invention. i

1, 2, 3-triazo1e N-CH N 11 -NH 1, 2, i-triazole Indawle NIL-N 2-mercapto-5-aminothiobiazole 5. Bic-NH =s O: I IH Thiohydantoin I 6. HaC-NH O-BH HaC-N Ethylenethiourea Mereapto benzlmidazolc 8. HNC=O Thiobarbituric acid HN-C Thiourazole Dihydro quinazolino 5, iii/E Perimidino HC-N Imldawlo Tetrazolo Tetrazolono Thioisatin HaG-CH:

1,2,3-triazolin Pyrazole anthrone troduced into the heterocyclic nuclei I do not mean that the final compound is necessarily formed by simple substitution starting with these two materials. The final compound may be formed by any suitable reaction which results in a compound having a heterocyclic portion as described above and a coupler portion or portions containing at least one group capable of reacting to form a, dye image.

The functional or reactive group common to the coupler compounds which react with primary aromatic amino developing agents to forma colored image is a reactive methylene or reactive ethanol group and this group may occur at various positions or more than a single position in the coupler molecule. By reactive methylene, I means a CH2 group which is reactive in the coupling process. The CH2 group usually is present between two negative centers as, for example, in the groups -COCH2-CO-,

. in many cases, be substituted without destroy- Cil ing chemical activity of the group. By reactive ethanol, I mean the group This group occurs in the phenolic and naphtholic coupler compounds which are reactive in the ortho or para position with respect to the position of the hydroxyl group.

The reactive NH or SH group of the heterocyclic systems herein disclosed reacts with metal salts to permit the formation of an insoluble salt such as a silver, gold, nickel, mercury or tin salt. Silver salts are preferred since a silver salt is ordinarily used in the product oi sensitive photographic layers and common silver salts such as silver chloride or silver bromide are suitable for the purpose of my invention. Other silver salts which may be used are silver ferricyanide, silver orthophosphate, silver arsenate, silver oxalate, silver cyanate, and silver citrate.

The reaction of the metal salts with the herein described heterocyclic system of the coupling compounds is ionic and rapid and involves a simple replacement of the hydrogen atom of the NH or SH group by the metal atom of the metallic salt employed.

The non-diffusing metal salts made according to my invention may be incorporated in single gelatin layers or layers of other colloidal materials such as cellulose esters or natural or synthetic resins. Non-diffusing silver salts according to my invention may also be incorporated in gelatino-silver halide emulsions intended for coating as superposed layers to form multi-color photographic elements.

The following example, which is illustrative only, indicates a, method of forming a multi-layer photographic element according to my invention. The coupler compound S-(ortho-hydroxybenzoylamin0)-indazole having the following formula:

and excess silver nitrate. H graphic emulsion which contains sensitive silver halide and silver salt of the coupler is coated on is dissolved in methyl alcohol in the amount of 2.5 grams in 40 cc. of methyl alcohol containing 0.8 gram of sodium hydroxide. This solution is added to one liter of 10% gelatin solution which is stirred vigorously while the temperature 'is maintained at 38-44" C. To this solution are added 150 cc. of l-N-silver nitrate with stirring. After a few minutes, 140 cc. of l-N potassium bromide solution are added slowly to the gelatin solution containing the silver salt of the coupler a support in the usual way. The coupler is retained in its respective layer by virtue of its insoluble salt generated by replacement of the imino' hydrogen atom of the indazole nucleus.

A second emulsion is produced in the same way using the coupler 5-(2- cyanoacetyl-5-sulfon-' the following formula:

x in the amount of 2.5-grams, using with'this 150 cc. of l-Nsilver nitrate solution and 142: cc. of l-N potassium bromide solution. The emulsion The resulting ph'otoformed in this way is coated over the first emulsion layer.

A third emulsion is formed according to the same method using 2.8 grams of the coupler 5- benzoyl' acetaminobenzutriazole which has the formula:

with which is used 150 cc. of 1-N silver nitrate solution and 140 cc. of l-N potassium bromide solution. This emulsion is coated on the second emulsion with a yellow filter layer in gelatin between the second and third emulsion layers. The yellow filter may consist of any suitable material such as colloidal silver in gelatin. The yellow filter is used for the purpose of preventing the action of blue light on the first and second coated emulsion layers.

The emulsion layers coated in this way produce respectively cyan, magenta and yellow images upon development with a p-phenylene diamine developing agent containing a primary amino group. The element may be exposed and devel-- oped directly to forms. negative color image or a positive image may be obtained by first developing in an ordinary black and white developer followed by color development of the remaining silver halide.

My invention will now be described with particular reference to the accompanying drawing. As shown in Fig. 1, it is a support of any suitable material such as cellulose nitrate, cellulose acetate, or other cellulose ester, paper, or other opaque material. On the support ill is coated the emulsion layer II which is a silver halide layer containing the silver salt of a heterocyclic-ringcontaining coupler according to my invention. Fig. 2 is a multi-layer element in which the support In is coated with layers l2, I3, and I4 sensitive, respectively, to the red, green, and blue regions of the spectrum. These layers each contain the silver salt of a heterocyclic-ring-containingcoupler, the coupler portion of which ordinarily is chosen so that it produces a dye on development which is complementary in color to the original sensitivity of the layer. It is to be understood that an element of this type may contain filter, subbing, antl-haltion, or other layers commonly used in such materials.

A developer suitable for either negative or posi tive development in colors of the elements described above is as follows:

Potassium bromide grams 2.5 Sodium sulfite do 05 Sodium carbonate "do---" 60 p-Aminodiethylaniline hydrochloride do 2.5 Water to liter 1 Development is preferably carried out for about ten minutes at 65 F. after which the element is treated with a ferricyanide and hypo bath to remove the silver and any undeveloped silver halide which the film contains. This bath may also re-" move any unused coupler in the layer although it is immaterial whether or not the unused coupler is removed.

My invention is capable of numerous variations and it isto be understood that it is to be considered as limited only by the scope of the appended claims.

What I claim is:

1. The method of producing a color-forming photographic emulsion which comprises incor porating in a colloidal material a coupler compound containing a heterocyclic nucleus having therein an imino group the hydrogen of which is replaceable by a metal atom to render the compound mon-diffusing, the lmino group being not more than two atoms distant from an atom which has an unshared pair of electrons, then treating the colloidal material with a metal salt more soluble than the metal salt of the coupler to replace the hydrogen atom of the imino group, and forming a sensitive silver salt in the colloidal material.

.2. The method of producing a color-forming photographic emulsion which comprises incorporating ingelatin a coupler compound containing a heterocyclic nucleus having therein an imino group the hydrogen of which is replaceable by silver to render the compound non-diffusing, the

- iriiino group being not more than two atoms distant from an atom selected from the group consisting of sulfur and nitrogen, which has an un shared pair of electrons, then treating the gelatin with a silver salt more soluble than the silver salt of the coupler to replace the hydrogen atom of the imino group, and forming a sensitive silver salt in the gelatin. r

3. The method of producing a color-forming photographic emulsion which comprises incorporating in gelatin a coupler compound containing a benzotriazole nucleus having therein an imino group the hydrogen of which is replaceable by silver to render the cbrnpound non-diffusing, the imino group being not more than two atoms dis tant from the nitrogen atom of the benzotriazole nucleus, which has an unshared pair of electrons, then treating the gelatin with a silver salt more soluble than the silver salt of the coupler to replace the hydrogen atom of the imino group, and

. forming a sensitive silver salt in the gelatin.

ing an lndazole nucleus having therein an imino group the hydrogen of which is replaceable by silver to render the-compound non-diffusing, the imino group being not more than two atoms distant from the nitrogen atom of the indazole nucleus, which has an unshared pair of electrons, then treating the gelatin with a silver salt more soluble than the silver salt of the coupler to replace the hydrogen atom of the imino group, and forming a sensitive silver salt in the gelatin.

5. The method of producing a colored photographic image in a gelatino-silver halide emulsion layer which comprises coupling the development product of an aromatic amino developing agent containing a primary aromatic amino group in a gelatino-silver halide emulsion layer with a non-diffusing coupler compound contained in said layer, comprising a silver salt of a heterocyclic nucleus containing a replaceable hydrogen atom on a negative atom not more than two atoms distant from an atom which has an unshared pair of electrons said coupler compound containing at least one group selected from the class consisting of methylene and ethenol which is reactive with the development product of aromatic amino photographic developers.

WILLARD D. PETERSON.

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